1. Field of the Invention
The present invention relates to an image processing technique of an image forming apparatus capable of printing a print job according to a print command and reprinting the print job according to a reprint command.
2. Description of the Related Art
When print data is to be printed, a stain on a printing paper or difference in color may be generated in a printed product. A user visually confirming the printed product may then be dissatisfied with the result.
In such a case, it becomes necessary for the user to re-transmit the same job from a host personal computer (PC) to a printer to output another printed product after confirming the printed product. Further, the host PC and the printer are required to perform the same printing process as the previous process in reprinting the print data.
In particular, if the host PC and the printer are located far apart, it becomes necessary for the user to walk back and forth between the host PC and the printer to re-transmit the same job to the printer.
To solve such a problem, Japanese Patent Application Laid-Open No. 2007-118239 discusses a technique in which the printer temporarily stores the data that has been once printed without deleting the data, so that the data can be reprinted by operating on the printer. In the above-described technique, the printer is capable of storing, when temporarily storing the print data, the print data corresponding to each job, and performing reprinting of the stored print data corresponding to a transmitted job or a plurality of jobs.
Further, in a normal printer, a toner remaining amount measurement unit measures a remaining amount of toner in a toner cartridge. If the toner remaining amount measurement unit detects that the remaining amount of toner is less than or equal to a threshold value, the printer determines that the toner has run out, and an error display determination unit then determines that an error has occurred. Upon determining the error, a display unit displays to the user that the printer is in a “toner run out (i.e., toner out)” state, and prompts the user to replace the toner cartridge.
However, when the display unit is displaying “toner out”, it does not necessarily indicate that there actually is no toner at all in the cartridge. In other words, the remaining amount of toner which is less than or equal to the threshold value may be a sufficient amount for printing to be performed without the print result becoming faint.
There are users who desire to print until immediately before the print result becomes faint and replace the toner cartridge after confirming that the print result has started to become faint.
For example, it is assumed that a user, who prints until immediately before the print result becomes faint, transmits 100 pages of a print job to the printer. Further, while the printer is performing the received job, the print result on the paper becomes faint from page 21, so that the user acquires a printed product in which the print results of page 21 to page 100 are faint.
If the user is not satisfied with the faint print results of page 21 to page 100, the user replaces the current toner cartridge to a new toner cartridge and reprints the job on the printer from the beginning, using the above-described reprinting function. As a result, the user can acquire a printed product in which the print results of page 21 to page 100 are not faint.
However, if the user cannot replace the toner cartridge until the printer completes printing of the transmitted job, it does not answer the user's demand to be able to replace the cartridge after confirming that the print result has started to become faint. In other words, the user cannot completely use the toner in the cartridge.
Further, when the printer performs initial printing of the job, 80 sheets of paper and time used for printing page 21 to page 100, in which the toner has become faint, become useless. Furthermore, if the user is satisfied with the printing result of the first 20 pages acquired in initial printing, the printing results of the first 20 pages acquired by the printer performing reprinting after the user replaces the cartridge become useless.
The above-described problem is not limited to the printer using the toner and similarly occurs in a printer using a recording agent such as ink.